cpufreq-cpu0.txt 1.2 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455
  1. Generic CPU0 cpufreq driver
  2. It is a generic cpufreq driver for CPU0 frequency management. It
  3. supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
  4. systems which share clock and voltage across all CPUs.
  5. Both required and optional properties listed below must be defined
  6. under node /cpus/cpu@0.
  7. Required properties:
  8. - operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt
  9. for details
  10. Optional properties:
  11. - clock-latency: Specify the possible maximum transition latency for clock,
  12. in unit of nanoseconds.
  13. - voltage-tolerance: Specify the CPU voltage tolerance in percentage.
  14. Examples:
  15. cpus {
  16. #address-cells = <1>;
  17. #size-cells = <0>;
  18. cpu@0 {
  19. compatible = "arm,cortex-a9";
  20. reg = <0>;
  21. next-level-cache = <&L2>;
  22. operating-points = <
  23. /* kHz uV */
  24. 792000 1100000
  25. 396000 950000
  26. 198000 850000
  27. >;
  28. transition-latency = <61036>; /* two CLK32 periods */
  29. };
  30. cpu@1 {
  31. compatible = "arm,cortex-a9";
  32. reg = <1>;
  33. next-level-cache = <&L2>;
  34. };
  35. cpu@2 {
  36. compatible = "arm,cortex-a9";
  37. reg = <2>;
  38. next-level-cache = <&L2>;
  39. };
  40. cpu@3 {
  41. compatible = "arm,cortex-a9";
  42. reg = <3>;
  43. next-level-cache = <&L2>;
  44. };
  45. };